Constants
by InfiniteImprobability
Summary: Charlie Eppes understands a lot of things...but there is one thing he will never understand. A look into the minds and relationship of the brothers.
1. Chapter 1

Disclaimer: I do not own Don and Charlie Eppes…but oh, how I wish I did

**Constants**

Chapter 1

Charlie was alone in the garage again. Escaping. Hiding from what he didn't understand. Charlie had spent his life decoding the deepest mathematical mysteries of the universe. With numbers, he was in control. Invincible. He lived for that thrilling moment of clarity when suddenly everything made sense. Numbers made things clear, understandable. Predictable.

But there were a lot of things he would never understand. Things that even the most brilliant of equations couldn't explain. Problems he couldn't solve. Take, for example, why he was here in the garage instead of helping his brother.

Charlie knew how hard it was for Don to ask for help. And he wanted to help. He truly did. But there was that little voice at the back of his mind, whispering doubts. _What if I'm wrong? What if I misinterpret the data? What if I miscalculate?_

He could never understand how Don did what he did every day. There were so many risks , so many variables. So many unknowns. And if he failed, the consequences were enormous. Charlie could not help admiring his brother.

He scribbled furiously at the board, blinking chalk dust from his watering eyes. He wasn't sure it was the dust that was making them water.

_Please, Don,_ he thought. _Don't do this to me. Don't leave me with equations that I can't solve._

He stared at the numbers and symbols scrawled on the chalkboard, his hand frozen in midair. The headphones clamped over his ears blasted Beethoven into his brain. The melodies always helped him to organize his thoughts. There was math even there, he knew. Even in the music. Patterns everywhere.

He had always been able to see these things. Patterns, solutions. He barely had to look at a problem and suddenly they were there, dancing before his eyes. Sometimes they were so simple and obvious he was amazed that everyone couldn't see them.

But they couldn't. Don couldn't. That was why he needed Charlie.

"_I want to help you", _Charlie whispered to himself. _"I know you need me, but I need you more. I need you more…."_

He set the chalk down, tore of his headphones, and ran his fingers through his unruly dark curls. He tried to tell himself not to be afraid…but how could he not be afraid when there was so much at stake? Don…lives…people.

Charlie glanced back up at his chalkboards. He knew too well what was holding him back. The ultimate unsolvable equation. The universe's biggest, deepest mystery. People. There were no patterns to describe their behavior, their thoughts, their motivations. The most complex mathematical theories were a walk in the park for Charlie Eppes, but human behavior was the one thing he had always failed to understand. It simply defied analysis.

Charlie sighed and sat down. The late afternoon sun slanted through the windows and he watched the dust particles dance in it. Why was it that he felt more of a connection with those minute particles of matter than with any human being?

Except Don. Don, in his own way, had always understood. He always knew what Charlie was trying to say, even when words failed him, as they so often did. Don was the constant.

Charlie turned and saw his brother standing in the doorway, silhouetted in the light from the dying sun.

"Hey, buddy," Don said. His voice was so warm and friendly. He always used that voice when he knew Charlie was distressed. Dust particles danced in the air, like a veil between the brothers.

"Don, I…"Charlie stammered. His head was too clogged with numbers and consequences. The words couldn't find their way through. He just looked at his brother, taking in the rolled-up shirt sleeves, loosened necktie, concerned eyes and knitted eyebrows. He had that intensely interested look he always wore when Charlie was explaining how some mathematical principle related to the current case.

"It's okay," he whispered. "Look, I know how you feel. And I know it's hard. Believe me, I know." The concern was still there, but his eyes were pleading now.

_Note to the reader: THIS IS NOT THE ONLY CHAPTER!" I guess the story (it's more of a drabble, really) could end here, but it doesn't There's another chapter, this time from Don's perspective, and an epilogue. ALSO: I don't know if the Eppes' garage has windows or not. I don't think it does…but for the sake of the story, I'm pretending it does. The dramatic light has to come from SOMEWHERE._


	2. Chapter 2

_Disclaimer: I don't own Don and Charlie Eppes. But I think you knew that. _

**Constants **

Chapter 2

"But…Charlie…we're counting on you."

Charlie turned away and stared at the nearest chalkboard, fingers resting on his temples. Don stared at the back of his head and wondered what was going on inside it. He looked so small and vulnerable…Don remembered seeing him as a little boy, barely nine years old, sitting in a high school classroom. The sight stirred the same emotions in him then as he was feeling now—concern, a deep paternal instinct, and a persistent but often-ignored twinge of jealousy.

"I know you're afraid, Charlie," Don said soothingly, moving a few steps closer, "But if you help us you won't have to be." He placed a hand on his brother's shoulder and followed his gaze up towards the blackboard. All he saw was indecipherable gibberish, but he knew what was behind it.

"I don't know if I can do it, Don. It's highly improbable…" Charlie looked up at Don, and once again Don saw the little boy. All Don wanted to do was protect that innocence…but there were other things he had to protect as well.

"Charlie…buddy…" Don moved closer to his brother and slipped an arm around his shoulders. Charlie stared listlessly at his shoes, curls falling into his wet dark eyes. "…I know that when it comes to numbers there is nothing you can't do. I remember when we were in high school…there you were, nine years old and acing calculus while I barely scraped by with C's in basic geometry…." Don smiled in spite of himself at those memories, ignoring the all-too-familiar twinge of jealousy that always accompanied such thoughts. He loved his brother more than anything, but he could not help being jealous. It was hard, having a brother like Charlie. Despite doing the best he could, Don could never hold a candle to is brother. Perhaps this was why he felt so incredibly protective of him.

"It's not beyond your ability, buddy. Nothing is beyond your ability. Something else is holding you back. Are you going to tell me what it is?"

Charlie looked up at don from behind his rumpled curls and smiled slightly. A feeling of warmth spread through Don's whole body at the sight. He was getting through. Even if it was just a crack in the mortar, the wall to Charlie's world was coming slowly down.

"I don't know how you do it, Don."

"Do what?"

"What you do. Your job. I'm not as strong as you, Don. I'm not an FBI guy like you. I can't pretend that I'm not afraid."

Don led his brother to a chair, shifted a stack of books and Charlie's laptop, and sat him down.

"Do you think I'm not afraid?" Don said with a chuckle. "Sometimes I go out on an assignment and I'm scared to death. But I remind myself that there are people who need me. Charlie, I wish I could protect you forever. Let you stay locked away in your ivory tower with your books and your equations until you had solved all of the mysteries of the universe, but…buddy…you have to understand. I need you now. I wish I could do this on my own, but Charlie, I can't. I need your help."

It hurt every time he said that. Don had asked his brother for help so many times he thought the pain would have dulled by now, but it didn't. And it probably never would. But Don was pretty good at ignoring his own pain when he knew there were others who were hurting more. He was worried about Charlie, and he was worried about the lives he felt slipping away every second Charlie hesitated.

If Don didn't know his brother so well he would think Charlie was being selfish for refusing to help him. But while Charlie's mind was a perpetual enigma, Charlie's heart was an open book. Don knew his brother's emotions; simple, strong, and rarely controllable. It was not selfishness that movitated him now. It was a deep, genuine concern for his family.


	3. Epilogue

_Disclaimer: Once again, Don and Charlie are (sadly) not mine._

_Note: This is the last chapter! Thanks to anyone who takes the time to review. It's much appreciated._

**Constants**

Epilogue

Charlie's eyes were burning from chalkdust and tears. Don's image swam in front of him. He reached out, took his brother's outstretched hand, and allowed himself to be pulled to his feet.

"What if I'm wrong, Don?"

"There's not much room for mistakes, Charlie. But you have to do what you can. I have faith in you."

Charlie smiled shyly at his own weakness as Don slapped him on the back. He didn't know what he would do without Don. He could tie the entire universe together into one beautiful equation and it would still have no meaning without Don.

Charlie Eppes understood a lot of things, but he would never understand human beings. They were rarely predictable and almost never logical. For the first time in his life, however, as he walked out of the dusty garage with his brother's arm around his shoulders, Charlie realized that maybe some things are not meant to be understood.

_And…that's all, folks. Short, I know. But, this was my first attempt at writing fanfiction, so I hope someone out there thought it was worthwhile. _


End file.
